Nondazzle lamp



Feb. 28, 1939. U R 2,148,574

NONDAZ ZLE' LAMP Filed May 21, 1956 3 Sheets-Sheet l L mp Mgknfor: PAULMULLER Attorney Feb 28, 1939.

P. MULLER NONDAZZLE L Filed May 21, 1936 AMP 3 Sheets-Sheet 2 F 7. I I19! I I 70 74 3 74. 7g

\ lm gnfor': 0

PAUL MULLER P. MULLER NONDAZZLE LAMP Feb. 28, 1939.

s Sheets-Sheet 3 Filed May 2l, 1936 ln l emon' 7 PAUL MULLER hi? tlorneycrease in the ratio Patented Feb. 28, 1939 UNITED STATES.

I PAT NONDAZZLE LAMP Paul Miiller, Berlin-Frledrichshagen, Germany,

assignor. to Julius schaft, Berlin, Germany Application May 21, 1936,No. 80,932 In Germany May 28,1935

Claims. (01. 240-41.s)'

This invention relates to non-dazzle lamps for illuminating streets,roads or the like, and is concerned primarily with headlamps mountedupon vehicles, although it is also applicable to stationary lamps.setIalong streets, roads and the like.

It is necessary in the illumination of motor roads that there shall be.a complete absence of dazzle for the drivers, zling light shall notissue from the lamps above a certain altitude or laterally beyond acertain angle. Care must therefore be taken that the light is sharplydefined or limited beyond these planes, and this requirement isfulfilled only to an incomplete extent with the usual constructions oflamps. The spatial construction of the illuminating element, e. g. thefilament of an incandescent lamp, opposes the sharp definition of thebeam. The different radius vectors, for example of a parabolicreflector, which even from the peak focal of 1:2, always give a hazyedge to the cone of light, so that the transition from complete darknessto maximum brightness occursyin an angle which does not allow a completefreedom from dazzle with the ranges of head-lights, for instance, whichare now required. In particular, the direction in which the constructionof motor roads now 'tends to develop, with long straight stretches topermit increased speeds, has made new demands in regard to theconstruction of car head-lights. It has become necessary to provide along range head-light which casts onto the road a beam that is sharplydefined at the upper edge. In addition it is required that the intensityor the light shall increase as it gets further away from the car, thelight source being utilized in the best possible way, whilst the angularrange covered by the head-light should decrease with increasing distancefrom the car. Y

According to the from the principles hitherto usual in the constructionof head-lights; and do not produce a beamof, suitable convergence bymeans simply of a lens disposed near the light source. Instead, Iarrange to illuminate a lens of great focal length bymeans. ofcondensing lenses, so that the said lens produces a sharply definedimage of the luminous area produced in the condenser system. I may alsoprovide baflles in front of the luminous area of the condenser systemfor the purpose of defining the beam vertically and laterally asdesired.

In order to create a beam the brightness of that is to say, that daz-.

width to the parameter in-" according to previous figures in presentinvention I depart which increases the greater the distance fromthe-light source, whilst its angular range decreases, I provide in thecondenser, according to a further feature of the invention, a pluralityof lenses or lens parts having increasing focal length and diameter fromlens to lens.

Other features and advantages of my invention, and methods of embodyingthe same will become apparent in the following description and appendedclaims.

Examples of embodiments of the invention are illustrated in theaccompanying drawings.

Fig. 1 shows in plane the condenser system which forms an important partof the present invention,

Figs.:2, 3 and 4 are more detailed illustrations showing the mountingand construction of the condenser lenses and prisms according to Figure1 in elevation, plan and side view respectively,

Figs. 5 and 6 are elevation and plan respectively of the samearrangement with the lens system raised,

Fig. 7 is a front view of the screen I 4, shown in Figure 3, arranged infront of the condenser system,

Fig. 8'shows the installation of a head-lamp the bonnet of anautomobile.

The system'illustrated diagrammatically in plan in Figure 1 includesbesides the light source I and the spherical mirror 2 and lens 3 twofurther lenses 3| and 32 with corresponding reflectors 2| and 22. Thetwo laterally disposed lenses 3|, 32 cause the formation of two furtherbeams which, however, diverge laterally very greatly. These lateralbeams are collected by two total reflecting prisms ill or two planemirrors and are guided towards the projection lens' 1 like the beam fromthe central lens. t

In order that a continuous unbroken and uniform illumination shall beobtained by the superposition of two cones of light consisting of brightand dark zones produced by a device as above described, the widths ofthe individual light beams and the interspaces must be exactly the same,and therefore the mirrors or prisms must be arranged very near to thecondensing lenses. Various difliculties arise in this connection,particularly in the assembly or cleaning of the apparatus. It is alsodiflicult to bring the light source exactly into the required position.

These difllculties are overcome by arranging the lenses surrounding thelight also, and also if necessary the concave mirrors on a carrier thatis readily removable from the apparatus. The light source itself mayeither be arranged also on this carrier so that it is removed when thecarrier is removed, or it may be arranged on the part of the apparatuscarrying the prisms, which is more advantageous in many cases. The lightsource is then easily accessible when the said carrier is removed, sothat not only can it be removed or replaced without difficulty, but alsoit is possible to eifect adjustment so that, for example, the light beamis cast at a predetermined place by a suitably arranged lens.

Figs. 2, 3 and 4 show an embodiment of such an arrangement in frontelevation, plan and side elevation respectively. The deflecting prismsI0 and the light source i are fixed to the base plate l'l. The lightsource is surrounded in a. semi-circle by three projecting lenses 3, 3|,32 of short focal length, and the circle is completed by the sphericalmirrors 2, 2| and 22.

To avoid the light reflected by the mirrors 2, 22, and 2| having to passthrough the light source, the centres of curvature I6 of these mirrorsare preferably displaced laterally somewhat away from the light source.

As shown in Fig. 3, thespaces between the two lateral projection lenses3|, 32 and the deflecting prisms ID are only very small. Likewise thespace within the prisms and the concave mirrors is practically whollytaken up by the glass parts surrounding the light source.

In front of the system the baflles l4 shown in Fig. 3 only, for the sakeof clearness are arranged in the focal plane of the head-light lens I.This lens I will in this case consist of two parts Ia and 1b, thecentres Ma and Mb of which are displaced somewhat by the width of thebaffies i l or by the same width as the spaces between the latter (seeFigure 2).

As shown in Figs. 5 and 6, the lenses 3, 3| and 32, and the concavemirrors 2, 2|, 22 are arranged in the carrier H3 in such a manner thatthe latter can be removed upwards from the rest of the system. When thiscarrier is removed both the prisms and the light source and also thecondensing lenses and mirrors are readily accessible for cleaning oradjustment purposes.

The present invention, be it understood, is not limited to the mountingof the light source on the base plate, and could, without substantiallymodifying the arrangement, be connected to the carrler I8, for examplebe removably fitted in said carrier so as to make the light sourceitself and the inner sides of the lenses and mirrors accessible for,cleaning purposes.

Movement of the. vehicle, due for example to the car being heavilyloaded above the rear axle may in certain circumstances cause the upperboundary of the cone of light, to be raised so much that oncoming usersof the road may be dazzled. Also when the car is travelling .overunclulated country and is for example on a rise, the cone of light israised'so high that dazzling may occur, whilst on the other hand whenthe car is travelling in a dip too short a stretch may be illuminated insome circumstances.

It is particularly advantageous for the baflie to be operable from thedriver's seat, since, as the upper boundary of the beam can be observedvery exactly, the driver is able to take care-that this upperboundary isalways below the eye level of the drivers of oncoming vehicles, theupper boundary being preferably so adjusted, for the sake of simplicity,that it lies below the headlights of the oncoming vehicles, Similarly wen travelling over hills the upperboundary of the beam can be kept tothe summit of the hill so as to avoid dazzling of oncoming drivers bylight passing beyond the summit, and when travelling down slopes thebeam can be elevated to such an amount as to illuminate a sufiici'entlylong stretch in front.

This adjustment of the upper boundary of the beam is quite suflicient toprevent any dazzle whatsoever, so that the necessity for anti-dazzlescreening is eliminated entirely.

Especial attention must also be given to ensure that the upper limit ofthe beam is under the eyelevel of oncoming drivers on the side nearer tothe oncoming drivers, that is to say on the left hand side in Germanyand other countries where drivers keep to the right of the road. Owingto the curvature or camber of the road however the beam is sometimesraised too high on this side due to the oblique position of the car.

In order to prevent this occurrence, according to a further feature ofthe invention, the upper tilting the condenser system and at the sametime turning the divided head-light lens, or by providing in front ofthe condenser system inthe focal plane of the projection lens a baiiflewhich shields the condenser system in such a way that the left-handcorner of the rectangular area of the distant beam is cut off.

Fig. '7 is a front view of the baffle arranged in front of the condensersystem for production of the remote beam and corresponding to the baflieshown in Figure 3. The inclined baflle cuts off a corner of the luminousarea formed by the condenser system, and thus the upper lefthand cornerof the head-light beam is removed.

In the foregoing description of the screen or bafiie II, it has beenassumed that the car in question is destined for use in a country wheredrivers take therighthand side of the road. It is obvious, however, thatin countries where drivers take the left-hand side of the road, thearrangement described must be reversed and the upper right-hand cornerof the cone of light out off. The baflie may therefore be so arrangedthat it is reversible without difficulty so as to permit adjustment whencrossing the border between two countries.

If with the arrangement described hereinbefore the dimensions areadopted which have been found by experiment to be especially suitable,that is a ratio between the focal length and the diamv bonnet, andarranging the condenser system, constructed in the manner previouslydescribed, directly in the dashboard so that the beam passes under thebonnet from the light source to the front lens. Withv this embodiment,which is illustrated in Fig. 8, it is also possible to 'make the angleof inclination of the beam displaceable rela tive to the axis of thecar. For this purpose the condenser system 3, 3|, 32 and the lightsource are mounted on a base plate 4|! joined to a partspherical disc 4|which slides on a similarly curved surface 42 that may be attached tothe back of the dash-board. If the sliding surface 4| is so constructedthat its centre of curvature coincides with the centre of the front lens1 it is possible to lower the beam of the head-light by moving thecondenser system upwards.

As indicated diagrammatically in Fig. 8, the condenser system may beshifted from-the driver's seat electromagnetically by means of a rodmechanism 43, a ratchet wheel 44 and two pawls 45, 46 moved by theironcores 4'land the coils 48. These coils can be switched on by pedals49, each depression of a pedal causing the ratchet 'wheel to be rotatedby the distance of one tooth and thus raising or lowering the head-lightbeam on step. Obviously, different ways of operating the movingmechanism are possible; for instance the rods may be moved by Bowdencable or by direct manual operation. It is also obvious that by virtueof the cQ-operating ball and ball-cup Y arrangement 4|, 42 shown inFigure 8,-the condenser system can be moved in a"horizontal as well asin a vertical direction.

The objective lens 1 is made in two parts as in connection with Figure1.

To simplify as much as possible the adjustment of the head-light beam,or the bailles, so that the driver can attend to this operation withouthis attention being taken off his driving, the'preferred constructionis, as illustrated in Figure 8, such that the movement of adjustmenttakes place in a plurality of successive steps effected by the hand knobor pedal, so that the driver can elevate or depress the beam by onestep,

i when he notices that the latter is too low or too high by pressing onthe knob or operating the pedal, without having to give his attention toobserve how much he must elevate or depress the beam orthe upperboundary thereof. Should he then notice that this single operation ofthe switch is not enough, he operates it a second time and if. necessarya third time.

step adjustment may of course also be applied to the lateral movement ofthe beam or of the lateral baflles.

What I claim is:

1. An automobile head light comprising a light source, a condensersystem comprising a plurality of lenses of short focal lengthsurrounding said light source crown-wise, reflecting surfaces adapted todeflect in the same direction the penoils of light issuing from saidcondenser lenses, a baflle in front of said condenser system having anaperture for each pencil of light, the width of each of said aperturesbeing equal to the width of the space between two adjacent apertures,and a lense of great focal length made up of two parts each-adapted togive a clearly-defined image of said baflie, the centres of said lensparts being spaced apart by a distance equal to the width of one of saidapertures.

2. -An automobile head light comprising a light source, a condensersystem comprising a plurality of lenses of short focal lengthsurrounding said light source, total-reflecting prisms adapted todeflect in the same direction the pencils-of hght issuing from saidcondenser lenses, spherical mirrors behind said light source adapted toreflect back the light falling thereon, a carrier to which the lightsource and said attached,'a further carrier to which said condenserlenses and spherical mirrors are attached and r-dapted to be fitted intosaid first-named This step-byprisms are carrier to which said lightsource and said prisms are attached, a further carrier to which saidcondenser lenses and spherical mirrors are attached and adapted to befitted into said firstnamed carrier, a baflle in front of said condensersystem and said prisms, said baflie having an aperture for each pencilof light, the width of each of said apertures being equal to the widthof the space betweenitwo adjacent apertures,'and a lense made up of twolong-focus lens parts adapted to ,give a sharply-defined image of saidbaflle, the centres of 'these lens parts being displaced from oneanother by a distance equal to the width of one tures.

4. An automobile head light comprising a source of light, a condensersystem comprising of said apera plurality of short-focus lensessurrounding said light source crown-wise, reflecting surfaces adapted todeflect in the same direction the pencils of light issuing from saidcondenser lenses,

a bathe in front of said condenser system, and two long-focus lens partsadapted each to give a sharp image of said baflie, the centres of theselens parts being spaced apart such a distance that'the two images of thebaflle form an unbroken bright area, and said baflle being obliquelyarranged sothat the upper corner of said bright areanearest'to themiddle of the road is cut ofi. y

5. In automobiles, a bonnet, a head light comprising a light source, acondenserv system comprising a plurality of short-focus lensessurrounding the light source, total-reflecting prisms adapted to deflectin the same direction the pencils of light issuing from the condenserlenses, spherical mirrors behind said light source adapted to reflectback the light falling on them, a carrier to which the light source andsaid prisms are attached, a further carrier to which said condenserlenses and spherical mirrors are attached and adapted to be slidden' insaid first-mentioned carrier, a ballie in front of saidcondenser system,said carriers and said baflle being disposed beneath the bonnet, and along-focus lens being arranged in the front wall of said bonnet andadapted'to give a sharply defined image of said baffie.

6. In automobiles, a bonnet, a head light comprising a light source, acondenser system comprising a plurality of short-focus lensessurrounding the light source, total-reflecting prisms adapted to deflectin the same direction the pencils of light issuing from said condenserlenses, spherical mirrors behind the light source adapted to reflectback the hght falling on them, a carrier to which the light source andsaid prisms are attached, a further carrier to which said condenserlenses and spherical mirrors are attached and adapted to be fitted insaid first-named car- 1 rier, a baflle in front of said condenser systemtures being equal to the width of the space be-" tween two adjacentapertures, said carriers and jective lens being arranged in the frontwall of said baflie being disposed beneath the bonnet, the bonnet, saidlens comprising two long-focus and an objective lens being arranged inthe front lens parts adapted each to give a sharply dewall of thebonnet, said lens comprising two fined image of said baflle, the centresof these long-focus lens .parts adapted to give a sharply lens partsbeing spaced apart by a distance equal 5 defined image of said baffle,the centres of these .to the width of one of said apertures.

lens parts being spaced apart by a distance equal 8. A head lightcomprising a light source, a to the width of one of said apertures.condenser system comprising a plurality of short- 7. In automobiles, anengine bonnet, a head focus lenses surrounding the light source,totallight comprising a light source, a condenser sysreflecting prismsadapted to deflect in the same tem comprising a plurality of short-focuslenses direction the pencils of light issuing from said surrounding saidlight source, total-reflecting condenser lenses, spherical mirrorsbehind the prisms adapted to deflect in the same direction light sourceadapted to reflect back the light fallthe pencils of light issuing fromthe condenser ing on them, a carrier to which the light source lenses,spherical mirrors behind the light source and said prisms are attached,a further carrier I adapted to reflect back the light falling theretowhich said condenser lenses and spherical on, a carrier to which saidlight source and mirrors are attached and adapted to be fitted prismsare attached, a further carrier to which in said first-named carrier, abaflle in front of said condenser lenses and spherical mirrors are saidcondenser system and said prisms and havattached and which is adapted tobe fitted in ing an aperture for each pencil of light, the saidfirst-named carrier, a bafile in front of said width of each of saidapertures being equal to condenser system and total-reflecting prismsand the width of the space between two adjacent having an aperture foreach pencil of light, the apertures, and lens means of great focallength width of each of said apertures being equal to ap ed o ve a ar ydefined image of the the widthof the space between two adjacentapbaffle. ertures, said carriers and baffle being displace- PAUL ablyarranged beneath the bonnet, and an ob-

